Process and apparatus for producing free nicotine from its salts



H. K. MCCONNELL PROCESS AND APPARATUS FOR PRODUCING FREE NICO'I'INE FROMITS SALTS Filed Aug. 2, 1922 Patented sept. 2, 1924.

UNITED STATES PATENT OFFICE.

HENRY K. MOCONNELL, OF RICHMOND, VIRGINIA, ASSIGNOR TO TOBACCO-BY-PROD-UCTS .AND CHEMICAL CORPORATION, OF LOUISVILLE, KENTUCKY, A. CORPORATIONOF DELAWARE.

PROCESS AND APPARATUS FOR ERODUCING FREE ANICOJIITNI] FROM ITS SALTS.,

Application tiled August 2, 1922. Serial No. 579,173.

To all whom it may concern:

Be it known that I, HENRY K. MoCoN- NELL, a citizen of the UnitedStates, residing at Richmond, county of Henrico, and State of Virginia,have invented certain new and useful Improvements in Processes andApparatus for Producin Free Nicotine from Its Salts, fully descri ed andrep-resented in the following specification and the lo accompanyingdrawings, forming a part of the same.

The present invention relates to an improved Yprocess for producing freenicotine froml its salts.

The object of the invention is to provide f a commercial process forlarge scale operation whereby stron solutions of free-nicotine may beobtaine from solutions of nicotine salts at a low labor cost.

With this general object in view, the process consists lin mixi anaqueousI solution of a nicotine salt with hydrated lime, subjecting themixture to dry heat (which, it has been discovered, may be at atemperature relatively high as compared with the temperatures heretoforeconsidered permissible with nicotine or its compounds), while at thesame time protecting the materials, vincluding the vapors, from accessof air, and leadlng oli' and condensing the vapors evolved from themixture by the heat.

Fer the purpose of carrying out the p-rocess conveniently on acommercial scale, a new apparatus has been devised which, however, formsno part of the present invention.

This new apparatus comprises a plurality of receptacles closed againstadmission of air, one, the retort or still, being heated by a suitablesource of heat, the second serving as a condenser, and the third servingas a receiver for the condensed aqueous solution of nicotine. Theprocess is carried out as a batch operation, but the appara-tus is soconstructed that the still may be quickly emptied of its spent materialsand a new charge supplied, while the receiver may be emptied from timeto time, so that the opera-tions may be carried out in rapid succes- 50sion.

In the best ,form of the apparatus, there is .an air pump in connectionwith the receiver at a point above the highest level to which thecondensate accumulates in the receiver. The air pump serves to draw olfthe air from the apparatus and, of course, to reduce the pressure withinthe apparatus. In practice I have found that a reduction of the pressureto about 24 or 25 inches of is all that is necessary.

The lnvention will be more specifically described in connection with theaccompanying drawings, in which,-

Fig. 1 is a diagrammatic View of an apparatus particularly suitable forcarrying out the invention.

I? ig. 2 is a sectional view through one of the stills.

Referring to the drawings, 1 is the still, Q-the condenser, 3 thereceiver for the condensate, and 4t the air-pump arranged to be operatedby any suitable means, as, for eX- ample, an electric motor, not shown.

The still 1 is suitably supported in a furnace, the walls of which areindicated at 5, and-is heated'below in any suitable way, as, forexample, by gas burners as indicated at 6, Fig. 2. 'Ihe individualburners are controlled by valves 7 and the gas main 8 is controlled by amain valve 9.

The still is of any suitable shape, but in the construction which hasheretofore been employed by me with good results, the bottom is flat andthe top arched. The still heads are bolted in place on the flanged endsof the body of the still, as will be clear from the drawings. A suitablepacking is employed between the contacting surfaces of the heads andflanges so as to prevent leakage of air, and in order to maintain theseair-tight joints, the ends of the still are allowed to project beyondthe furnace so that they will be air-cooled.

The head at one end of the still is provided with an opening throughwhich spent material may be removed from the still, this opening beingclosed by a removable closure device. In the present example, the holeis circular and is tapped to receive a screw-threaded plug 10 having apolygonal head to which a wrench may be applied.

The still is provided with suitable means for charging it. In thepresent example, this means consists of a lling pipe 11 provided with avalve 12 and extending from the top of the still toward th'e botto'm ofthe oor. A receptacle 13, filled with the new charge, may be placed atthe lower end of the filling pipe and elevated so that the said pipewill enter the receptacle. When the valve 12 is opened while theair-pump is in operation, the new charge will be driven by the exterioratmosphere into the still 1, whereupon the valve 12 is closed.

The still 1 is connected with the condenser 2 by a pipe 1 4. Thecondenser 2 is cooled in any suitable way, as, for example, by locatingit in a tank 15 supplied with cooling water by a water-inlet pipe 16, asuitable water overflow pipe 17 also being provided.

The bottom of the condenser 2 is connected with the receiver 3 by a pipe18. The air pump 4 is connected to the receiver by a pipe 19. Thereceiver may b e emptied by a discharge pipe 20 having a valve 21.

In carrying out the process, a suitable aqueous solution of a nicotinesalt is used as the starting material. In practice the nicotine sulphateor chloride is usually employed, and generally it is advantageous to usea concentrated solution.

The solution of nicotine salt is thoroughly mixed with hydrated lime,which, of course, is a fine owder. It is important to use freshly hyrated lime, because old material has an appreciable amount of carbonateof lime, which is disadvanta eous.

The mixture of hydrated ime and nicotine salt solution should be made inthe proportion of 1.5 parts by weight of lime to 10 parts byl weight ofnicotine solution of 40% strength, although these proportions may bevaried somewhat in practice without materially affecting the results.

The mixture, which is a thick Huid mass, may then be charged into aretort or still so as to form a layer lof considerable depth therein.The still is in connection with a suitable condenser preferablywater-cooled. Air is removed from the still and condenser. in anysuitable way, as by injecting an inert gas, for exam le, nitrogen, or byblowing `out the air wit sutlicient steam, whereupon thelsteam is cutott'. Preferably, however, the air is removed with an air-pump.`

The still is then heated externall to give a temperature of the vaporsof a out 400 to 500 F. It has been found that this can be done withoutinjury to the` product. This is contradictory to the previous View inthe art that nicotine com ounds and particularly free nicotine woul bedecomposed at such high temperatures. In fact, 1n carrying out myprocess in the apparatus heretofore described, I have carried thetemperature as high as 900 vF. in the vapor comprising 32 pounds ofhydrated lime and i 211 pounds of a 40% aqueous solution of nicotine sulhate, I have found that substantially a 1 the free nicotine will beevolved in about 13 hours, if the retort or still be maintained at atemperature of about 400 to 500 F.

The new process has many important advantages over the processesheretofore employed for obtaining free nicotine.

One important advantage over rior processes using steam for driving olf)the free nicotine is that the solution obtained by me is at least asstrong as the solution of the nicotine salt used in starting, because noadditional water-vapor is introduced during distillation. In fact, inpractice, the solution of free nicotine obtained by my process issomewhat more concentrated than the solution of nicotine salt, becausesome of the water vapor is not condensed with the nicotine solution.

A further important advantage 1s a greater efficiency of operation.Prior processes have shown as their best results a recovery of about 83%of the nicotine in the starting'solution. My new process in every dayoperation has given a recovery of 95% even at a low temperature of about350 F. and as high as 98% recovery at the temperatures of 400 to 500 F.

Still another great advantage of the process is that itis relativelyrapid because at the higher Itemperatures the free nicotine goes offmore rapidly. This permits a greater output with a more compactapparatus and with a lower labor charge per unit of free nicotine. Themore compact apparatus of course reduces the investment charge. Forthese reasons, the total cost of production of free nicotine ismaterially reduced.

` What I claim is:

1. The process of obtaining free nicotine from solutions of its salts,which consists in mixing hydrated lime with an aqueous solution of anicotine salt, subjecting the mixture to dry heat while excluding theair from it, and carrying olf and condensing the vapors. f-

2. The process of obtaining free nicotine, which consists in preparinga. mixture of hydrated lime and an a ueous solution of a nicotine salt,subjecting e mixture to a dry heat While under a pressure less thanatsaid solution, subjecting the mixture to e. mospheric, and carryingofiJ and condensing temperature of about 40G-500 F. under a E0 thevapors. pressure of about 24 to 25 inches of mercury,

3. The process of obtaining free nicotine, conducting o'i the vapors andcondensing S which consists in preparing a mixture of them.

hydrated lime and an aqueous solution of In testimony whereof, I havehereunto set nicotine salt in the proportion of about 1.5 my hand.pounds of lime to 10 pounds of nicotine in HENRY K. MCCONNELI-

